This invention relates to electric incandescent lamps, more particularly incandescent automotive lamps.
The well-known S-8 automotive lamp includes a glass envelope cemented in a brass, double contact, bayonet base and has been the industry standard for 70 years. The S-8 lamps are used in automotive lighting assemblies, particularly rear and front directional lights, reverse lights, fog lights, and brake lights. More recently the S-8 lamp is also available with an insulation base of plastic or ceramic. The base includes a depending portion lead-support located at its bottom with wire terminals of the lamp extending alongside and wrapping around the depending portion lead-support.
S-8 lamps suffer from a known disadvantage of corrosion of the metallic components of the lamp and its socket. For instance, because of a conventional loose seal between the base of the lamp and its socket, dust, dirt, and moisture from condensation and dampness infiltrate the lamp socket. Consequently, in brass-based lamps the base itself will corrode; in insulation-based lamps the wire terminals will corrode; and in both lamps the metallic components of the lamp socket will corrode.